Re: Writing own source disk

On 04/06/2024 02:35, Keith Thompson wrote:

Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

bart <bc@freeuk.com> writes:
[...]

I assume you can use __FILE__ with #embed? (I can do that with my
version of it).

>
Yes, but not reliably.
>
__FILE__ expands to "The presumed name of the current source file (a
character string literal)".  That's rather vague.
>
With gcc and clang, it expands to the file name argument given to the
compiler, or to the argument of the #include directive.  The running
program may or may not be able to access the source file using that
name.  The source file might not even exist when the program runs.

 I was thinking of using __FILE__ to access the source file at run time.
#embed is of course handled at compile time.  It's very likely, but
still not quite guaranteed, that `#embed __FILE__` will be able to
access the source file.
 

The key question for that will be directory handling.  If everything is being done within the same directory, than I'd expect "#embed __FILE__" to work fine.  But if you are calling the compiler from a different directory, specifying a path for the source file, that might not be reflected in __FILE__.  The result could vary between compilers.
There is also the possibility that the search path for #embed might result in finding a different file with the same name.  But I think that would probably need specific command-line switches to specify the #embed search path (again, this will be compiler-specific).